The present invention relates to a silicon carbide power device having a protective diode and the method for manufacturing the power device.
A silicon carbide power device including a junction field effect transistor (JFET) is proposed in JP-A-2000-312008. However, when the proposed device is used as a switching device such as an inverter for controlling a motor, there is the following problem in the proposed device. The proposed device is relatively readily destroyed by static electricity generated in the manufacturing process, by overheat due to an excessive current caused when the motor is locked, or by surge energy due to counter electromotive force generated when the inverter controls the motor. In addition, the proposed device includes a gate and a channel, and the gate is not insulated from the channel region by an oxide film as is in a MOSFET. Therefore, if an avalanche breakdown is caused at a PN junction in the proposed device, the current generated by the avalanche breakdown flows from the gate into a circuit that controls the gate to destroy the circuit.